Childhood depression constitutes a major public health concern, requiring effective interventions. The effects of treatments for childhood depression are relatively modest and short-lived, with sizeable percentages of children who maintain depressive symptoms following treatment. A potential barrier to treatment success is the single uniform format of treatment protocols, addressing all depressed children similarly, regardless of clinical presentation. One strategy for addressing this barrier is to personalize treatment, fitting intervention to the specific needs of the children being targeted. This approach is consistent with the strategic plan of NIMH to emphasize the development of personalized interventions. Studies have documented the importance of family context in the development and maintenance of childhood depression; however, the limited number of clinical trials that involved caregivers provided mixed results, with only some youths benefiting from caregiver involvement in treatment. A logical first step in personalizing treatment is to develop decision rules about which children are likely to benefit from caregiver involvement in treatment, and at what point in treatment caregiver involvement should occur. The proposed K- award will take the first step toward addressing these key personalizing questions, using the Sequential, Multiple Assignment, Randomized Trial (SMART) design, an experimental method that is well-suited to the development of personalized treatments. The proposed K-award fits well with the PI's research interests in the development and dissemination of evidence-based treatments for depressed children, and with the PI's long-term career goals of becoming an independent effectiveness and dissemination researcher in the area of childhood depression. The PI's previous research experiences include development of a psychotherapy manual focusing on positive parenting and assessing it, together with an individual CBT treatment, in two treatment studies. The proposed project will focus on the first step in the development of personalized treatment for depressed children, piloting use of the SMART design. The study has two aims. Aim 1 includes the refinement of the individual CBT and caregiver-child treatment manuals for use in the SMART trial. Refinement will be conducted using feedback from primary mentor (Dr. John Weisz) and CBT and parent training experts. Aim 2 includes a pilot study of the SMART experimental design, with 48, 8-12 year-old children who meet criteria for Major Depressive Disorder and/or Dysthymic Disorder. The pilot study will provide information about the acceptability of the treatment manuals, assessments, and study procedures and about the feasibility of the two-step randomization used in the SMART design. The resulting information will inform the development of a full-scale properly-powered SMART trial (to be proposed in a later application). The long-term objective is to use the SMART trial methods to guide development of personalized treatment for child depression. The PI's immediate career goals for the K-award emerge from her long-term career goals and fit well with the proposed project. Goal 1 is enhancement of training in cognitive behavioral strategies and parent training for treatment of child depression, needed for refinement of the individual and the caregiver-child treatment manuals. Goal 2 is obtaining advanced training in methods for enhancement of caregiver involvement in the treatment. Goal 3 is obtaining advanced training in innovative experimental methods, particularly the SMART experimental design, with the developer of the design (Dr. Susan Murphy, co-mentor for this project), and through coursework, workshops, and practice. Learning from Dr. Murphy will build the PI's expertise as an expert in the use of the SMART experimental design and will promote the success of the pilot study, the later full-scale SMART trial, and the development of personalized treatment for depressed children. The career training goals and the research plan outlined in this proposal will provide the PI with the experience and expertise needed for an independent research career in the field of childhood depression treatment.